Mariah Carey — Hail Caesar! Diva Signs On For Huge Vegas Payday

EXCLUSIVE

Go over Britney Spears, it’s Mariah Carey, Bitch! The singer has officially signed on as the newest resident diva in Las Vegas … TMZ has learned.

Caesars Palace got their wish … we’re told that Mariah snuck into Vegas last week to seal the deal. Need proof? We’ve got video of Carey and her entourage leaving the Palace Cheesecake Factory, escorted…